If the grid goes down how long does it take to step it up again? If transformers have been destroyed? They take years to make. How can a replacement transfor

If the grid goes down how long does it take to step it up again? If transformers have been destroyed? They take years to make. How can a replacement transformer be built with no power? How will you charge your car or pump fuel into it? How will the refineries make fuel? And as for the bunkers: if civilization is destroyed, once your supplies are exhausted you emerge to…? There aren’t any grocery stores.